1. Field of the Invention
The present invention relates to an arrangement structure of a starter motor in an all-terrain vehicle.
2. Description of Background Art
In general, a vehicle suitable for traveling on all-terrain such as a three-wheel buggy or a four-wheel buggy, for example, an all-terrain vehicle (hereinafter referred to as ATV) is well known. Such a vehicle is typically provided with a front wheel shaft and a rear wheel shaft provided at the front and rear of a vehicle frame, a front wheel and a rear wheel provided on the front wheel shaft and the rear wheel shaft, an engine provided between the front wheel shaft and the rear wheel shaft, a saddle-type seat provided on the upper portion of the vehicle frame, a bar-shaped handle provided in front of the saddle-type seat and supported by the vehicle frame, and a foot-rest disposed between the front wheel shaft and the rear wheel shaft and disposed on the vehicle frame.
The vehicle of this type has a design in which a minimum road clearance is sufficiently secured and a weight distribution of the vehicle is considered, so that it can travel on all terrain.
In the structure described above, a starter motor is provided for enabling the user to start the engine in a state of being seated on the saddle-type seat. The starter motor is normally arranged behind the engine and in an upper portion of an crankcase (For Example, Patent Document No. JP-A-10-121933).
On the other hand, although it is not the ATV having the structure described above, a motorcycle having the starter motor for the engine on the front side of the vehicle with respect to a vertical line including a center point of a crankshaft of the engine and downwardly of the horizontal line including the center point of the crankshaft of the engine is proposed (for example Japanese Patent Document No. 3261966).
However, in Japanese Patent Document No. JP-A-10-121933, since the starter motor is arranged in the upper portion of the crankcase, the position of the center of gravity of the engine is high, which leaves a problem in adjustment of the weight distribution of the ATV. On the other hand, in Japanese Patent Document No. 3261966, since the starter motor is disposed downwardly of the center point of the crankshaft, better adjustment of the position of the center of gravity is achieved
However, in Japanese Patent Document No. 3261966, since an oil filter, which is lighter than the starter motor, is located below the starter motor, the position of the center of gravity of the engine becomes inevitably high, which also leaves a problem in adjustment of the weight distribution.